Liquid-fuel pump



May 1930- A. E. BERDC JN 1,760,856

LIQUID FUEL PUMP Filed Jan. 27, 1928,

im w mun Win 2 TTORNEY Patented May I930 UNITED STATES PATENT OFFICE ALBERT E. IBEBIDON, OF DETROIT, MICHIGAN, ASSIGNOR TO A C SPABK IPLUG COMPANY, OF FLINT, MICHIGAN, A CORIPORA'JZ'ION' OF MICHIGAN LIQUID-FUEL PUMP Original application filed October 6, 1927, Serial No. 224,325. Divided and this application filed January i 27, 1928. Serial No. 249,809.

This invention relates to fluid pumps, par-' ticularly pumps for supplying liquid fuel to internal combustion engines and the pres-' vide a self-regulating, constant stroke mp Patent 1,647,768.

which will automatically govern itse f according to varying requirements, and which will be capable of delivering the fluid under a desired pressure.

The foregoing and other desirable objects are attained by certain novel features of construction, combinations and relations of arts, all as will appear in the course of the ollowing specification.

The drawing accompanying and forming part of this specification illustrates one practical embodiment of the invention and it should be understood that the structure may be modified and changed without departure from the true spirit and broad scope of the invention as hereinafter defined and claimed.

Figure 1 is a vertical sectional view of 'a form of the pump combined with a reserve fuel tank.

Figure 2 is an enlarged cross sectional view as taken substantially on the plane of line 22 of Figure 1. V

In the structure illustrated, the pumping is eflected by a flexible diaphragm 3 clamped between a base part 4 and a cover part 5, the base part having a cavity forming a pump chamber 6 with a valved inlet 7 and a valved outlet 8, constructed as inthe 'Berdon The diaphragm is shown as actuated by a pump rod 9 pivoted at 10 to a lever 11, which latter 1s plvotally mounted at ,one end at 12 and engaged at its opposite end between the flanges of a spool 13secured on a reciprocating member 14, which may be one of the valve tap ets of an internal combustion engine whic the pump furnishing with fuel. The pump rod is shown as having an 'upper screw threaded portion and a lower reduced screw threaded portion and the diaphragm is shown as secured between washers 15 on thereduced ortion of the rod and clamped tight against is e shoulder provided at the end of the upper larger portion of the rod by a clamp nut 16 on the lower reduced portion 17 of the rod. p

The diaphragm is usually of relatively thin and quite flexible materialso as to properly' follow the pumping movements of the rod. ,This inherent flexibility, to an extent, limits or determines the action of the pump, particularly in the larger pump sizes.

To control the flexibility without losin advantages of the same, there are provided in the illustration, spring plates 17, 18, above I and below the diaphragm, radially slotted as at 19, to form inwardly pro ecting spring fingers 20,overlying the opposite faces of the diaphragm and having their tip portions 21 turned outwardly or away from the general plane of the diaphragm. The upturned tips of the upper set of spring fingers are shown engaged by a pressure plate 22, and in similar fashion, the downturned tips of the lower set of. spring fingers are engaged by a pressure plate 23. These plates are shown flanged at their centers so as to slide freely over the pump rod and they are shown loaded by springs 25 and 26,'whose tensions are independently adjustable by nuts27, 28, screwed on the rod and acting against, abutment washers or cups 29, 30. a

The spring fingers resiliently confine the outer portions of the diaphragm between them and under normal or average operation of the pump, cause the outer portion of the diaphragm to follow the central portion so as to accomplish the maximum pumping effect. The force of the springs 25, 26 may be independentlyadjusted to secure just the desired effect and the force of these springs may vary for diflerent size diaphragms and in accordance with the pressure. The heavier the springs are made, the fuller the action of the diaphragm will be. The pressure plates 22, 23, may be so related to the clam ing washers 15 that the latter will'serve as a lit-- -ments for the plates, preventing too great pressure being applied.

The spring fingers and pressure plates at opposite sides of the diaphragm enablethe pump to be entirely self-regulating, the diaphragm varying its efiecting pumping area constant, the diaphragm may automatically.

in accordance with requirements. It will be seen that with an increase of pressure in the pump chamber, the diaphragm will flex upwardly, raising the upper spring fingers and upper pressure plate more or less against the tension of spring 25, and that with a sufficient reduction in pressure in the pump chamber, the diaphragm will flex the lower spring fingers and force the lower pressure plate down- Wardly against the tension of spring 26. Thus, with the stroke of the pump remaining regulate its effective area to pump less than the normal, or in fact, no liquid at all. The

outlet or the inlet either may be completely closed without injuring the pump, which may continue in operation with its constant stroke, merely regulating its effective area one way or the other to accommodate itself to the existing conditions. The pump structure is shown in the present application combined with a reserve fuel tank 31, the outlet from the pump chamber discharging into a delivery tube 32, extending down intothe tank and the tank normally discharging through a stand pipe 33 rising to a predetermined level in the tank. When it is desired to utilize the reserve body of fuel thus created, a plug 34 is unscrewed. to open up an emergency valve 35, discharging out through the same outlet fitting 36 used by the stand pipe.

While in the illustration the pump is protected by the two spring loaded pressure plates against either a closed inlet or a closed outlet, it will beobvious that one or the other pressure plate may be eliminated if it is desired to protect the pump only against one or the other of these two conditions. The presence of the two pressure plates, however, is desirable because of the greater uniformity of pressure limits. It will be understood that the loading springs are preferably stressed to give only after a predetermined pressure has been attained, whereas the resilient confining and diaphragmishaping fingers commence to give with the development of pressure and in proportion to the pressure. These resilient fingers, therefore, serve fully to protect the diaphragm against straining and the pressure plate or plates insure efiicient pump I operation.

What is claimed is: 1.--In a pump of the character disclosed,

- the combination of a diaphragm, spring fingers restraining said diaphragm to a normal flexure but yieldable to permit abnormal fiexure of the diaphragm, means for imparting pumping strokes of substantially uniform length to the body of said diaphragm independently of said spring retaining fingore, and resiliently yieldable means engaging a portion of said fingers.

2. In a pump of the character disclosed, the combination of a diaphragm, spring'fingers restraining said diaphragm to a normal flexure but yieldable to permit abnormal flexure of the diaphragm, a spring loaded pressure plate acting on said spring restraining fingers and means for imparting a substantially constant pumping stroke to the. body of said diaphragm independently of said spring restraining fingers.

3. In a pump of the character disclosed, the combination of a pumping diaphragm, spring fingers engaging opposite faces of said diaphragm to restrain the same to a definite normal movement but independently yieldable to permit abnormal flexure of the diaphragm, spring loaded pressure plates bearing on the fingers at the opposite sides of the diaphragm and means for imparting a substantially constant pumping stroke to the body of said diaphragm independently of said spring restraining fingers and independently ,of said spring loaded pressure plates.

4. A pump of the character disclosed, comprising in combination, a flexible diaphragm, means for positively imparting pumping movements thereto in both directions, means for applying a yielding restraining force to a portion of the face'of said diaphragm, said restraining means operative on the diaphragm independently of and apart from the pumping movements, and means to render the pumping effect thereof dependent upon the pressure of the pumped fluid on said diaphragm.

5. A pump comprising in combination, a flexible diaphragm rigidly held at its peripheral portion but free for pumping movements in its central portion, means for reciprocating the free central portion of the diaphragm, a spring plate overlying the diaphragm, said spring plate being rigidly held at its peripheral portion and having yielding spring portions over the free central portion of the diaphragm, and separately yieldable means engaging said spring portions, to vary the pumping effect of uniform reciprocations of said central portion.

6. A pump comprising in combination, a flexible diaphragm rigidly held at its peripheral portion but free for pumping movements in itscentral portion, means for reciprocating the free central portion of the diaphragm and a spring plate overlying the diaphragm, said spring plate being rigidly held at its peripheral portion and; having yielding spring portions over the free central portion of the diaphragm and a pressure plate resiliently bearing on the central yielding portions of the spring plate.

7. A pump comprising in combination, a flexible diaphragm rigidly held at its periphrocating the free central portion of the diaphragm, a spring plate overlying the diaphragm, said spring plate being rigidly held at its peripheral-portion and having yielding spring portions over the free central portion of the diaphragm, a spring plate held in similar fashion at the opposite side of the diaphragm and having spring fingers hearing on the free portion at such opposite side of the diaphragm, and means to render the pumping eifect thereof dependent upon the pressure of the pumped fluid on said diaphragm.

8. A pump comprising in combination, a flexible diaphragm rigidly held at its peripheral portion but free for pumping movements in its central portion, means for reciprocating the free central portion of the diaphragm and a spring plate overlying the diaphragm, said spring plate being rigidly held at its peripheral portion and;,having yielding spring portions over the free central portion of the diaphragm and a spring plate held in simi lar fashion at the opposite side of the diaphragm and having spring fingers bearing on the free portion at such opposite side of the diaphragm and independently yieldable spring tensioned pressure plates bearing on the spring fingers at opposite sides of the dia-' phragm.

9. A pump comprising in combination, a flexible diaphragm secured at its edges and free for pumping movement in its central portion, operating means connected with said central portion for imparting pumping strokes thereto and spring fingers overlying and yieldingly regulating the flexure of the' diaphragm and hence the pumping action of the same, an end of each of said fingers being curved away from said diaphragm.

10. A pump comprising in combination, a flexible diaphragm secured at its edges and free for pumping movement in its central portion, operating means connected with said central portion for imparting pumping strokes thereto, spring fingers overlying and yieldingly regulating the flexure of the diaphragm and hence the pumping action of the same and a spring tensioned pressure plate bearing on said spring fingers and regulating the action thereof.

11. In a pump of the character disclosed, the combination of a diaphragm having a flexible pumping portion, means for imparting pumping impulses to said flexible portion of the diaphragm, spring means positioned to control the'flexure thereof, and means acting on said spring means to vary the pumping effect of the flexible portion of the diaphragm.

12. In a pump of the character disclosed, the combination of a' diaphragm having a flexible pumpingportion, means for impart ing pumping impulses to said flexible portion of the diaphragm, spring means positioned to control thevfiexure and hence the pumping bearing on and controlling said spring means.

13. In a pump of the character disclosed, the combination of a diaphragm having a flexible pumping portion, actuating means 'for imparting pumpingimpulses to said flexible pumping portion, actuating means engaged with said flexible portion, confining means at opposite sides of said flexible portion for regulating the flexure thereof and independently yieldable control means for said confining means.

15. A pumphaving a pump chamber pro- I vided with valved inlet and outlet, a diaphragm having a flexible portion'forming a wall of the pump chamber, a reciprocating actuating member engaged with said flexible pumping portion of the diaphragm, a plate secured over the diaphragm and having r'esilient spring fingers overlyin the flexible portion of the diaphragm, sai minating short of that part of the diaphragm engaged by the actuatin means, and means to render the pumping ect thereof dependent upon t e pressure of the pumped fluid upon said iaphragm. Y

16. A pump having a pump chamber provided with valved inlet and outlet, a diaphragmhaving a flexible portion forming one wall of the pump chamber, a reciprocating connectionjengaged with said flexible portion fingers ter-- of the diaphragm, resilient spring elements of increasingly greater resiliency toward the actuated portion of the diaphragm positioned to exert a shaping influence on the flexible portion of the diaphragm, and means to render the pumping eflect thereof depend-1 valved inlet and outlet,.a flexible diaphragm positioned betweenthe base andlcover and forming a flexible wall of the ump chamber, plates clamped between the ase and cover in position underlying and overlying the diaphragm, said plates having inwardly extending substantially radial spring fingers bearing on the diaphragm and regulating the flexure thereof, an operating connection engaged with the diaphragm independently of said regulating plates, and means to render the pumping effect thereof dependent upon the pressure of tlie pumped fluid upon said diaphragm. I x

18. A pump comprisinga pump base and cover, said base-having a pump chamber with valved inlet and outlet, 3. flexible diaphragm positioned between the base and cover and forming a flexible wall of the pump chamber, plates clamped between the base and cover in position underlying and overlying the diaphragm, said plates having inwardly extending substantially radial sprlng fingers bearing on the diaphragm and regulating the fiexure thereof, an operating connection engaged with the diaphragm independently of said regulating plates and independently yieldable adjustably tensioned control members engaged-with the inner ends of the spring fingers.

In testimony whereof I afiix my signature.

ALBERT E. BERDON. 

